A so-called “chocolate lover” in Russia has vowed to never eat another bar again after he opened a newly purchased package and found a parasitic worm, Central European News reported.

“I’d made a cup of coffee, and was settling in front of the TV down when I opened it and saw this little white worm crawling across the top,” Peckish Erast Zubarev, 34, told CEN.

“I was told by my mate it was a parasitic threadworm that lives in the intestine,” Zubarev said.

Threadworms can grow up to about a half an inch and lay eggs in the gut, causing itching around the anus, CEN reported.

Zubarev went back to the store where he purchased the chocolate to complain, but employees reportedly told to write a note in the visitors’ book.

“I have never heard of anything so ridiculous, and I told the checkout girl this too. She said they are the regulations, and the visitor book was the place for complaints,” Zubarev told CEN.

A store spokesman told the news agency that items of “improper quality” may come directly from the manufacturer, and the store is unaware of it.

A spokesman for Rospotrebnadzor, the Russian consumer protection association, told CEN that he viewed the video online and “it looks more like a caterpillar to me, but without a complaint there is nothing we can do anyway.”

As for Zubarev, he has sworn off chocolate bars.

“I was so repulsed by this I just can’t imagine having another one,” Zubarev said.